Well tools and gripping members therefor

ABSTRACT

AN IMPROVED SLIP OR GRIPPING MEMBER THAT IS USED ON WELL TOOLS TO LOCK THE WELL TOOLS AT A DESIRED LOCATION IN A WELL BORE. THE SLIP IS PIVOTALLY LOCATED ON THE WELL TOOL AND IS PROVIDED WITH WALL ENGAGING TEETH ON RELATIVELY OPPOSITE SIDES THEREIN ADJACENT EACH END. THE SLIP IS POSITIONED BETWEEN RELATIVELY MOVEABLE ABUTMENTS THAT ARE MOVED TOGETHER TO ENGAGE THE ENDS OF THE SLIP AND PIVOT THE SLIP INTO AND OUT OF ENGAGEMENT WITH THE WELL BORE WALL. ONE END OF THE SLIP, REFERRED TO AS THE ACTIVE END, IS PROVIDED WITH A PLURALITY OF SPACED POINTS OR SURFACES WITH EACH BEING ARRANGED TO ENGAGE THE ADJACENT ABUTMENT WHEREBY THE POTIMUM FORCE WILL BE EXERTED ON THE SLIP TO MOVE THE SLIP TEETH INTO HOLDING ENGAGEMENT WITH THE WELL BORE WALL. THE OPPOSITE END OF THE SLIP, REFERRED TO AS THE PASSIVE END, IS SIMILARLY PROVIDED WITH A PLURALITY OF POINTS OR SURFACES THAT ARE ARRANGED TO ENGAGE THE OTHER ABUTMENT AND ARE LOCATED IN SUCH A POSITION AS TO CAUSE THE SLIP TEETH TO MOVE RELATIVELY AWAY FROM THE WELL BORE WALL. THE POINTS OR SURFACES ON EACH END OF THE SLIP ARE ARRANGED TO MAINTAIN A RELATIVELY CONSTANT RATIO BETWEEN THE DISTANCE FROM EACH OPERATIVE POINTS ON THE ACTIVE AND PASSIVE ENDS AND THE ADJACENT WELL BORE WALL THEREBY PERMITTING THE PREDETERMINATION OF THE FORCE THAT IS EXERTED ON THE SLIP DURING SETTING OF THE WELL TOOL.

Feb. 6, 1973 N. w. READ WELL TOOLS AND GRIPPING MEMBERS THEREFOR FiledDec. 20, 1971 5 Sheets-Sheet 1 INVENTOR'.

NORMAN W.. READ FIG. IA

4 Au 0M ATTORNEY Feb. 6, 1973 N. w. READ ,7 ,984

WELL TOOLS AND GRIPPING MEMBERS THEREFOR Filed Dec. 20, 1971 5Sheets-Sheet 2 24 FIG.2B

INVENTORI 52 NORMAN w. READ F I G. 2 A y ATTORNEY Feb. 6, 1973 N. w.READ 3,714,934

WELL TOOLS AND GRIPPING MEMBERS THEREFOR Filed Dec. 20, 1971 5Sheets-Sheet 3 F l J I 8 J &

JNVENTOR 3 NORMAN W. READ ATTORNEY Feb. 6, 1973 N. w. READ 3,714,984

WELL TOOLS AND GRIPPING MEMBERS THEREFOR Filed Dec. 20, 1971 5Sheets-Sheet 4 INVENTOR NORMAN W. READ ATTORNEY FIG. 4

Feb. 6, 1973 N. w. READ WELL TOOLS AND GRIPPING MEMBERS THEREFOR 5Sheets-Sheet 5 Filed Dec. 20, 1971 INVENTOR NORMAN W. READ mow ATTORNEYUnited States Patent 3,714,984 WELL TOOLS AND GRIPPING MEMBERS THEREFORNorman W. Read, Dallas, Tex., assignor to Dresser Industries, Inc.,Dallas, Tex. File Dec. 20, 1971, Ser. No. 209,744 Int. Cl. EZlb 23/06U.S. Cl. 166-134 Claims ABSTRACT OF THE DISCLOSURE An improved slip orgripping member that is used on well tools to lock the well tools at adesired location in a well bore. The slip is pivotally located on thewell tool and is provided with wall engaging teeth on relativelyopposite sides therein adjacent each end. The slip is positioned betweenrelatively moveable abutments that are moved together to engage the endsof the slip and pivot the slip into and out of engagement with the wellbore wall. One end of the slip, referred to as the active end, isprovided with a plurality of spaced points or surfaces with each beingarranged to engage the adjacent abutment whereby the optimum force willbe exerted on the slip to move the slip teeth into holding engagementwith the well bore wall. The opposite end of the slip, referred to asthe passive end, is similarly provided with a plurality of points orsurfaces that are arranged to engage the other abutment and are locatedin such a position as to cause the slip teeth to move relatively awayfrom the well bore wall. The points or surfaces on each end of the slipare arranged to maintain a relatively constant ratio between thedistance from each operative points on the active and passive ends andthe adjacent well bore wall thereby permitting the predetermination ofthe force that is exerted on the slip during setting of the well tool.

BACKGROUND OF THE INVENTION This invention relates generally to improvedwell tools and to improved slips or gripping members for use on suchwell tools. More particularly, but not by way of limitation, thisinvention relates to an improved slip of unitary construction that ispivotally mounted on the improved well tool and that is arranged to bemoved by abutments on the well tool into holding engagement with thewell bore wall.

This invention is an improvement to the slip or gripping memberdescribed and claimed in the US. Pat. No. 3,548,936, issued Dec. 22,1970.

Packers and other well tools constructed in accordance with thedisclosure of US. Pat. 3,548,936 have functioned satisfactorily, butcertain problems have arisen due to peculiarities of the oil industry.It has long been the practice in the oil industry to manufacture tubulargoods such as casing having a single nominal outside diameter in amultiplicity of inside diameters depending on the pressure or structuralrequirements. For example 7" nominal outside diameter casing may varyfrom 17 lbs. through 32 lbs. per foot in several weights with the insidediameters of the pipes varying from 6.538" to 6.094, respectively.

In accordance with this inside diameter variation, the manufacturers ofoil tools generally manufacture tools for use in 7" nominal casing ofseveral sizes or a single size tool that has the interchangeable partsof appropriate sizes. A single tool that will operate in all the varioussizes will considerably reduce inventory, costs, warehousing and supplyproblems.

The production of a dilferent tool to fit each size and weight of casingpresents an intolerable situation in that for 7 nominal casing alone,the manufacturer must produce and stock at least six or seven differenttools. In the 3,714,984 Patented Feb. 6, 1973 second situation, themanufacturer can, perhaps, get by with two or three different tools withseveral different sizes of interchangeable parts for each. Either ofthese solutions gives rise to the necessity for design, manufacture andwarehousing of many components.

A well packer or anchor incorporating slips or gripping membersconstructed in accordance with this invention can, for the most part, beutilized in most casing weights for a given nominal outside diameter.Thus, one object of the invention is to provide an improved well toolhaving an improved gripping member that can be utilized over arelatively large range of casing Weights.

Another object of this invention is to provide an improved gripping forwell tools wherein such tools can be utilized in a plurality of wellbore diameters or casing weights.

A further object of this invention is to provide an improved well tooland gripping member for such well tools that permits a substantialreduction in parts and tool inventory.

One other object of the invention is to provide an improved grippingmember for well tools that is arranged whereby the setting force exertedon the gripping member can be predetermined.

SUMMARY OF THE INVENTION In one aspect, this invention provides animproved gripping member for well tools that can be used in conduitshaving a preselected range of inside diameters. The tool includes anelongated tool 'body, spaced first and second abutments moveably carriedby the tool body and means for moving the a-butments relatively togetherand apart. The improved gripping member includes a unitary body memberarranged to encircle a portion of the tool body between the abutmentsand pivotal thereon between set and unset positions. The body memberincludes first and second ends engageable with the abutments to pivotthe gripping member and a plurality of spaced conduit engaging portionslocated adjacent each end and on opposite sides of the body member. Eachof the conduit engaging portions is engageable with at least one of theconduits having an inside diameter within the preselected range. Theunitary body member also includes a plurality of spaced surface portionslocated on the first end. A respective one of the surface portionsengages the first abutment when a corresponding conduit engaging portionis in engagement with the conduit.

In another aspect, this invention contemplates an improved well tool foruse in conduits having a preselected range of inside diameters. Theimproved tool comprises elongated body means, spaced first and secondabutment means carried on the body means, means for moving the abutmentsrelatively toward and away from each other, and a unitary grippingmember that encircles a portion of the body means between the abutmentand that is pivotal relative to the body means between set and unsetpositions. The unitary gripping member is constructed as mentionedhereinbefore.

The foregoing and additional objects and advantages of the inventionwill become more apparent as the following detailed description is readin conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1A and 1B are views, partly incross section and partly in elevation, of an improved tool constructedin accordance with the invention. The tool is illustrated with thevarious components in the positions they occupy as the tool is runthrough the conduit.

FIGS. 2A and 2B illustrate the tool of FIGS. 1A and 1B in the setposition in a well casing or conduit.

FIG. 3 is a fragmentary view of a portion of the well tool of FIG. 1Athat more clearly illustrates the construction and arrangement of theimproved gripping member when the tool is set in a relativelylightweight conduit.

FIG. 4 is a view similar to FIG. 3, but illustrates the improvedgripping member set in a heavier weight conduit having the same nominaloutside diameter.

FIG. 5 is another view similar to FIG. 3 but illustratmg the improvedgripping member set in still a heavier weight conduit having the samenominal outside diameter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to thedrawing and to FIGS. 1A and 1B 1n particular, shown therein is animproved well tool generally designated by the reference character 10.The well tool includes an elongated tool body 12 that 15 comprised of aplurality of components that are threadedly connected to facilitate themanufacture of the tool body 12. At its upper end, the tool body 12 isprovided with a thread 14 for connecting the tool 10 with tub1ng (notshown) that is used to run the well tool 10 into a well bore. At itslower end, the tool body 12 is also provided with threads 16 that may beutilized to connect additional tools or other apparatus to the lower endof the well tool 10. Mounted on the exterior of the tool body 12 is ahousing 18 that extends coaxially along a portion of the tool body 12and terminates at its lower end in an inwardly extending flange 20forming a downwardly facing abutment 22.

A slip or gripping member sleeve 24 encircles a portion of the tool body12 in sliding relationship thereto. The slip sleeve 24 is provided withan outwardly extending annular flange 26 that is arranged to engage theflange 20 on the housing 18 for purposes that will become more apparenthereinafter. A lug 27 on the sleeve 24 is arranged to engage surface 29on the gripping member 30 to exert an unsetting force on the grippingmember 30 during release of the tool 10. Disposed within the housing 18is a helical compression spring 28 that has its upper end engaging thetool body 12 and its lower end engaging the flange 26 on the slip sleeve24. The slip sleeve 24 extends through a unitary gripping member 30 thatis arranged for pivotal movement on the tool body 12 and the slip sleeve24.

The gripping member 30 is provided with an upper or passive end 32 thatis engageable with the abutment 22. The configuration of the upper end32 will be described in detail hereinafter in connection with adiscussion of FIGS. 3 through 5. The gripping member 30 also includesupper wall engaging portion 34 and a lower wall engaging portion 36. Aspring 38 mounted on the gripping member 30 has one end in engagementwith the slip sleeve 24 to bias the gripping member 30 toward theretracted position as illustrated in FIG. 1A. The gripping member 30also includes a lower or active end 40 that is engageable with anupwardly facing abutment 42 that comprises a portion of an upper packerthimble 44. The lower end 40 and the wall engaging portions of thegripping member 30 will also be described more fully in connection withFIGS. 3 through 5.

The upper packer thimble 44 slidingly encircles the tool body 12 belowthe gripping member 30 and includes a lower abutment 46 that is inengagement with the uppermost of a plurality of resilient packing rings48. The lowermost of the packing rings 48 is in engagement with anannular abutment 50 that forms the upper end of a lower packer thimble52. The lower packer thimble 52 is also slidingly disposed on the toolbody 12 and terminates at its lower end in a downwardly facing abutment54.

A lower slip sleeve 56 slidingly encircles the tool body 12 and has anoutwardly extending annular flange 58 on its upper end that is disposedwithin and engages the interior of the lower thimble 52. The slip sleeve56 ex tends through a lower gripping member 60 that is constructedsimilar to the gripping member 30 except that it is inverted on the welltool 10. The gripping member 60 includes springs 62 that have one end inengagement with the slip sleeve 56 to aid in urging the gripping member60 toward the retracted position as illustrated in FIG. 1B. The grippingmember 60 includes an upper or active end 64 and a lower or passive end66. The upper end 64 is engageable with the abutment 54 while the lowerend 66 is engageable with and upwardly facing abutment 68 on a dragblock assembly 70. The upper and lower ends 64 and 66 of the lowergripping member 60 are also constructed as will be described inconnection with the gripping member 30 which is illustrated in FIGS. 3through 5.

The lower end of the slip sleeve 56 is formed into an exterior flange 72that is disposed within the drag block assembly 70. As constructed, thedrag block 70 is moveably positioned on the tool body 12 for both theirrotational and longitudinal movement. Such movement is controlled by ashear pin 74 that operates within a J-slot 76 formed in the tool body12.

Between the abutment 68 formed on the drag block assembly 70 and theshear pin 74, a plurality of spring loaded drag blocks 78 are located inopenings in the body of the drag block assembly. The drag blocks 78 arearranged to frictionally engage the interior wall of the conduit orcasing 80 (see FIG. 2B) as the Well tool 10 travels therethrough so thatrelative movement can be accomplished between various moveablecomponents of the tool 10 as is well known in the oil tool art.

Referring to FIGS. 2A and 2B, the well tool 10 is shown therein in theset position in a casing 80, which will normally be disposed in a wellbore (not shown). Upon reaching the desired position in the well borefor setting the well tool 10, a tubing (not shown) connected to theupper end of the tool is rotated to the right and lowered so that theJ-slot 76 formed in the tool body 12 moves downwardly with respect tothe shear pin 74 that is mounted in the drag block assembly 70. Due tothe frictional engagement of the drag blocks 78 with the conduit 80, thedrag block assembly 70 and the lower gripping member 60 remain in arelatively fixed position.

The upper gripping member 30, the upper thimble 44, the packing rings48, and the lower thimble 52 move downwardly with the tool body 12. Thedownward movement brings the downwardly facing abutment 54 intoengagement with the upper or active end 64 of the lower gripping member60, causing the lower gripping member 60 to rotate into the set positionas illustrated in FIG. 2B. As illustrated in FIG. 2A, the upper grippingmember 30 has also moved relatively downwardly with its lower or activeend 40 in engagement with the upwardly facing abutment 42 on the upperthimble 44. The upper gripping member 30 is rotated toward the setposition, but is not firmly set.

Additional downward movement of the tool body 12 exerts a force throughthe spring 28 and the upper slip sleeve 26 on the upper thimble 44,deforming the paok- 1ng rings 48 outwardly into sealing engagement withthe conduit 80. Simultaneously, the upper gripping member 30 has, in amanner of speaking, ratcheted downwardly in the conduit 80 under theinfluence of the downwardly facing abutment 22 on the housing 18 whichis in engagement with the passive end 32 of the upper gripping member30. When the packing elements 48 are fully deformed, farther downwardmovement of the upper thimble 44 is prevented, and the full force of thetubing is exerted on the upper gripping member 30.

Since the lower gripping member 60 is in engagement with the casing 80and fully set and the downwardly facing abutment 22 on the housing 18 isin engagement with the passive upper end 32 of the upper gripping member30, the force exerted on the upper gripping member 30 to cause thesetting thereof and deformation of the packing ring 48 is determined bythe dilference in the lever arms or couples acting on the grippingmember.

As can be seen more clearly in FIGS. 3, 4 and 5, the upper or passiveend 32 of the gripping member 30 and, similarly, lower end 66 of thelower gripping member 60 are provided with discrete abutment engagingportions 32a, 32b and 320. The lower or active end 40 of the grippingmember 3G is also provided with discrete abutment engaging portions 40a,40b and 400. Similarly, the upper end 64 of the lower gripping member 60will be provided with such contact engaging portions.

In addition, the active end 40 of the upper gripping member 30 isprovided with a contact or set-out portion 41 near the periphery thereofand adjacent the wall engaging portion 36. The set-out portion islocated to provide an initial contact point with the abutment 42 thathas maximum torque upon engagement to quickly and easily initiate thepivotal movement of the gripping member 30 toward its set position.

The lever arms previously referred to are identified in FIG. 3 as A1 andA-2, in FIG. 4 as B-1 and B-2, and in FIG. 5 as C-1 and C-2. The leverarms are created due to the engagement of the teeth or conduit engagingportions adjacent the passive ends of the gripping members 30 and 60.The provision of the discrete contact portions on the active and passiveends of the gripping members and, thus, the control of the length of thelever arms permits the predetermination of the force that will beexerted in setting the gripping members.

For example, if the well tool is to be set in a conduit having a thinwall such as illustrated as being the casing 80a, the lever arm A-l isthe distance from the wall of the conduit 80a to the contact portion 32aon the gripping member 30 which is in engagement with the downwardlyfacing abutment 22 on the housing 18. The

lever arm A-2 extends from the wall of the conduit 80a to the contactportion 40a which is in engagement with the upwardly facing abutment 42on the upper thimble 44.

, Since the setting force on the gripping member is determined by thedifference in the lever arms A-1 and A-2, it is possible to select thelocations of the contact portions 32a and a so that the desired force isexerted on the gripping member 30.

As mentioned earlier, one object of this invention is to provide animproved well tool 10 and an improved gripping member that can beutilized in conduits having varying inside diameters. Accordingly, FIG.4 illustrates the gripping member 30 in the set position in a conduit 8%which has the same nominal outside diameter as the conduit 80a but has asmaller inside diameter. In order for the well tool 10 to besuccessfully set in the conduit 8%, the gripping member 30 has beenconstructed so that the lever arms B-1 and B-2 have substantially thesame ratio as did the lever arms A-1 and A-2 with the gripping member 30set in the conduit 80a. In view of this, and even though the well tool10 is being run in conduit 8% which has a different inside diameter thanthe conduit 80a, the forces on the gripping member 30 can be controlledso that the same setting force is attained.

As a further illustration of the versatility of the invention, FIG. 5illustrates the gripping member 30 set in a conduit 800 having still asmaller inside diameter than did the conduit 80b. In this instance, thecontact portions 320 and 46c are in engagement with the downwardlyfacing abutment 22 and the upwardly facing abutment 42, respectively,providing lever arms 0-1 and C-2 that have the same ratio orsubstantially the same ratio as did the lever arms A-l, A-2 and 13-1,B-2. Thus, it can be readily appreciated that the setting force exertedon the gripping member 30 in the casing 80c will be substantially thesame as that on the gripping member 30 when set in the casing 80a or80b.

It should also be pointed out that the wall engaging portion 36 andsimilarly the wall engaging portion 34 on the gripping member 30 areprovided with arcuate configurations. The wall engaging portions areroughly divided into wall engaging portions 36a, 36b and 360 asillustrated in FIG. 3. Although there may be some overlap in the wallengaging portions, it can be seen that the wall engaging portion 36a isin secure holding engagement with the conduit a as shown in FIG. 3, thewall engaging portion 36b is in secure holding engagement with theconduit 80b as shown in FIG. 4, and the wall engaging portion 36c is insecure holding engagement with the conduit 800 as illustrated in FIG. 5.It can be further seen that there is a relationship established betweenthe respective abutment engaging portions 32a, 40a and the wall portion36a; the abutment engaging portions 32b, 40b and the wall engagingportion 36b; and, the abutment engaging portions 32c, 40c and the wallengaging portion 360. Furthermore, this relationship providesappropriate lever arms whereby the setting force to be exerted on thegripping member 30 is substantially the same regardless of the innerdiameter of the conduit 80. As previously mentioned, the well tool 10can then be utilized throughout the varying inner diameters of conduit80 which have a single nominal size or diameter.

The ability to perform in such varying inside diameters with the welltool 10, permits the manufacturer to utilize a single tool and, thus,reduces his inventory parts and reduces the manufacturing and designproblems to the very minimum.

The well tool 10 illustrated is a retrievable tool, that is the welltool can be unset and removed from the conduit 80 when desired.Retrieval is accomplished by rotating the tubing (not shown) and thetool body 12 to the right and raising the tubing and tool body. As thetool body 12 rotates, the shear pin 74 moves into a portion of theJ-slot 76 that permits the tool body 12. to be moved upwardly relativeto the drag block assembly 70.

As the tool body 12 is raised, the flange 20 on the lower end of thehousing 18 engages an exterior flange 26 on the upper slip sleeve 24.This engagement moves the upper slip sleeve 24 relatively upwardlybringing the abutment 27 thereon into engagement with the surface 29 onthe upper gripping member 30. Continued upward movement of the tool body12 and the slip sleeve 24 exerts a force on the upper gripping member 30lifting and rotating the gripping member 30 to the retracted positionillustrated in FIG. 1A.

Release of the upper gripping member 30 permits the upper thimble 44 tomove upwardly, releasing the deforming pressure on the packing rings 43which return to the position illustrated in FIG. 1A. As the tool body 12is pulled upwardly, the upper thimble 44 is pulled upwardly therbey andalso pulls the lower thimble 52 upwardly, moving the downwardly facingabutment 54 out of engagement with the upper or active end 64 of thelower gripping member 60*. When this occurs, the springs 62 carried bythe lower gripping member 60* pivot the gripping member 60 into theretracted position illustrated in FIG. 2A.

In the event that the lower gripping member 60 does not release, thelower slip sleeve 56, which is pulled upwardly by the lower thimble 52,pulls the drag block assembly 70 moving the upwardly facing abutment 68thereon into engagement with the lower or passive end 66 of the lowergripping member 60. This engagement exerts a positive force on the lowergripping member 60, rotating the member 60' into the retracted or unsetposition. As soon as the lower gripping member 60 has been released, theentire well tool 19 is in the position illustrated in FIGS. 1A and 1Band is in condition to be removed from the well bore.

It will be understood that the foregoing detailed description of thepreferred embodiment is presented by way of example only and that manychanges and modifications can be made thereto without departing from thespirit and scope of the invention.

The embodiments of an invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An improved gripping member for well tools that are useful inconduits having a preselected range of inside diameters, the toolincluding an elongated tool body spaced first and second abutmentsmovably carried by the tool body and means for moving the abutmentsrelatively together, said gripping member comprising:

a unitary body member arranged to encircle a portion of the tool bodybetween the abutments and pivotal relative thereto between set and unsetpositions, said body member having first and second ends engageable withthe abutments to pivot said gripping member,

a plurality of spaced conduit engaging portions located adjacent eachsaid end on opposite sides of said body member, each said conduitengaging portion being engageable with at least one of said conduitshaving an inside diameter within the preselected range, and

a plurality of spaced surface portions located on said first end, one ofsaid surface portions engaging said first abutment when a respectiveconduit engaging portion is in engagement with one of the conduitswithin the preselected range of inside diameters.

2. The improved gripping member of claim 1 and also including:

a plurality of spaced surface portions located on said second end, thesurface portions on said second end being located to pivot said grippingmember toward the unset portion when in engagement with the secondabutment; and

wherein the surface portions on said first end are located to pivot saidgripping member toward the set position when in engagement with thefirst abutment.

3. The improvement gripping member of claim 2 wherein said surfaceportions are located on said gripping member with a substantiallyconstant ratio between the distances from each of the conduits to arespective surface portion on said first end to a respective surfaceportion on said second end when said gripping member is disposed in anyconduit having an inside diameter within the preselected range.

4. An improved well tool for use in conduits having a preselected rangeof inside diameters, said tool comprismg:

elongated body means having a longitudinal axis;

spaced first and second abutment means carried by said body means;

means for moving said first and second abutment means relatively towardand away from each other; and

a unitary gripping member encircling a portion of said body meansbetween said abutment means and pivota1 relative to said body meansbetween set and unset positions, said gripping member having first andsecond ends engageable with said first and second abutment means,respectively, to pivot said gripping member,

a plurality of spaced conduit engaging portions located adjacent eachsaid end and on opposite sides of said gripping member, each saidconduit engaging portion being engageable with at least one of saidconduits having an inside diameter within the preselected range, and

a plurality of spaced surface portions located on said first end, one ofsurface portions engaging said first abutment means when a respectiveconduit engaging portion is in engagement with one of said conduitswithin the preselected range of inside diameters.

5. The improved well tool of claim 4 and also including a plurality ofspaced surface portions on said second end located to pivot saidgripping member toward the unset position, one of the surface portionson said second end being engageable with said second abutment means whena respective one of the surface portions on said first end is inengagement with said first abutment means.

6. The improved well tool of claim 5 wherein the surface portions onsaid first and second ends are located on said gripping member atpositions to maintain the ratio substantially constant between thedistances from each of the conduits within the preselected range to therespective surface portion on said first end and to the respectivesurface portion on said second end.

7. The improved well tool of claim 6 and also includmg:

third abutment means carried by said body means;

packing means encircling a portion of said body means between said firstand third abutment means, said packing means being deformable to form aseal between said body means and the conduit; and

said means for causing relative movement of said first and secondabutment means also includes means for moving said first and thirdabutment means toward and away from each other to deform and to releasesaid packing means.

8. The improved well tool of claim 7 wherein said means for causingrelative movement of said first and third abutment means includes:

a fourth abutment means carried by said body means;

a second gripping member pivotal with respect to said body means betweenset and unset positions and located on said body means between saidthird and fourth abutment means, said second gripping member havingfirst and second ends with a plurality of spaced surface portions onsaid first end located for engagement with said third abutment means inrespective set positions of said second gripping member and with atleast one surface portion on the second end of said second end arrangedto engage said fourth abutment means to pivot said second grippingmember toward the unset position.

9. An improved gripping member for well tools that are useful inconduits having a preselected range of inside diameters, the toolincluding an elongated tool body, spaced first and second abutmentsmovably carried by the tool body and means for moving the abutmentsrelatively together, said gripping member comprising:

a unitary body member arranged to encircle a portion of the tool bodybetween the abutments and pivotal relative thereto between set and unsetpositions, said body member having first and second ends engageable withthe abutments to pivot said gripping member,

a plurality of spaced conduit engaging portions located adjacent eachsaid end on opposite sides of said body member, each said conduitengaging portion being engageable with at least one of said conduitshaving an inside diameter within the preselected range, and

a contact portion on said first end located proximate the conduitengaging portion adjacent said first end and engageable with the firstabutment to initiate pivotal movement of said gripping member to the setposition.

10. The improved gripping member of claim 9 and also including:

a plurality of spaced surface portions located on said first end, one ofsaid surface portions engaging said first abutment when a respectiveconduit engaging portion is in engagement withone of the conduits withinthe preselected range of inside diameters.

References Cited UNITED STATES PATENTS 3,416,610 12/1968 Prescott166-206 X 3,419,079 12/1968 Current 166-206 3,485,181 12/1969 Hahs166214X 3,548,936 12/1970 Kilgore 16612l DAVID H. BROWN, PrimaryExaminer U.S. Cl. X.R.

